This invention relates to method devices and system for fluidic pumps. More particularly it pertains to/gas pumps, gas flow control and fluid level sensing. This invention optimizes the efficiency of electromagnetic reciprocating pumps such as those described in U.S. Pat. No. 4,154,559, U.S. Pat. No. 4,170,439, and U.S. Pat. No. 5,052,904 (among others) by control of the pump driving frequency and drive current. Energy savings are realized in the pump operation by eliminating off-nominal pump drive conditions. In practice, electromagnetic reciprocating pumps are driven by the continuous 60 Hz sinusoidal AC service available from utility power companies (50 Hz in some countries other than the US). In their design and manufacture they are made to pump most efficiently at or near the utility power frequency when they are operating at or near the nominal conditions of their intended application range. As conditions vary from the nominal, efficiency and flow also vary. Off nominal pump performance may become so compromised that flow ceases well before the pump capacity is exceeded.